In recent years there has been a growing interest in the collection of human fetal blood. Such blood is a source of numerous blood factors that have important commercial and therapeutic uses in a number of different fields, such as tissue culture, bone marrow transplantation, stem cell collection, pharmacology, and biological research. Currently, the sole commercial source of human fetal blood is blood obtained from the placenta and umbilical cord of newborns after delivery. This blood is often referred to as cord blood, as it is typically obtained by draining the placenta and umbilical cord through the severed umbilical cord after delivery.
The most commonly used commercial method for collecting cord blood is venipuncture, which is known in the art as a closed circuit system. Typically, cord blood is collected through one needle inserted in the vein of the umbilical cord, into a bag, though in some procedures, a syringe may replace the bag. In contrast, an open circuit procedure is one where blood flows freely from the severed end of the umbilical cord into a container. Closed-circuit methods aim mostly at reducing the risk of contamination of the collected blood, which occurs very commonly during the open-circuit procedures. However, the main advantage of open-circuit systems is that there is no resistance to the flow of blood, and therefore, the average amount of blood collected by open circuit systems is larger than the average amount collected when using closed-circuit methods. Consequently, an open-circuit method, in which the blood sample was kept sterile, thereby avoiding contamination, would be very beneficial in the art.
In order to collect as much blood as possible, the force of gravity is exploited, hence, the placenta is held at a higher position than the collecting implement. In addition, the placenta is usually “milked”, either by the contractions of the uterus, if still in the mother's body, or, if not, it may be compressed by some sort of apparatus, such as a container connected to an inflatable bladder. Some procedures for collecting cord blood compress the umbilical cord as well as the placenta.
Many methods for collecting cord blood have been developed. Several such methods and devices relating to various types of systems for collecting blood from the umbilical cord are disclosed in, for example, the following patents: U.S. Pat. Nos. 5,372,581, 5,575,796 and 5,053,025.
Paderni discloses in U.S. Pat. No. 6,302,854 a general method for collecting fluids, particularly cord blood. According to Paderni's method, a portion of the cord is cleaned, disinfected, and cut and then the cord is coupled to the connection system, which locks the cord in place. No description of how these steps are accomplished is provided in the patent. Finally, the connection system is then connected to a collection container. After expulsion from the mother's body, the placenta is placed in a container where positive pressure is applied to it. Optionally, Paderni states, without describing how, that negative pressure can be applied to the blood collection container in order to facilitate the outflow of blood from the umbilical cord.
In U.S. Pat. No. 6,190,368, to Kuypers, et. al., is described an apparatus and a method for collecting blood from an umbilical cord. The apparatus disclosed consists mainly of a housing having an inner region adapted to retain an umbilical cord in a desired location and an opening through which the cord extends from this inner region to a region external to the housing. In their procedure, the cord is cut by a blade coupled to the housing and through the newly cut end of the umbilical cord the blood flows, aided by gravity, into a blood collection region of the housing. In addition they disclose a receiving container for the placenta which is equipped with an inflatable bladder or other means for compressing the placenta.
Many other methods and apparatuses for collecting cord blood are disclosed in the prior art. Some of these methods describe “open-circuit” systems, in which the collected blood is vulnerable to contamination. In addition, many of the devices are expensive, and sometimes complicated to use, requiring a great deal of skill on part of the person collecting the blood.
The main limitation of the prior art is the amount of uncontaminated cord blood collected. This amount is highly important since it determines the quantity of stem cells that can be extracted from the collected sample. Currently, the average amount of blood collected is 80 ml, though a skilled collector might collect up to 150 ml of the approximately 250 ml present. The amount of stem cells extracted form an average blood sample is usually sufficient for transplants in subjects weighing up to about 44 kg, therefore not allowing a treatment solution conditions arising after childhood. The amount of blood collected is usually very dependent on the skill of the collector.
After birth there is a fast deterioration in the blood vessel structure and coagulation of the blood takes place very rapidly. Since most existing collection procedures are comparatively slow, much of the cord blood coagulates in the placenta and in the umbilical cord and many blood vessels collapse, causing blood to be essentially trapped in the placenta and the umbilical cord before it can be collected.
It is highly desirable to develop a procedure which will maximize the amount of uncontaminated blood extracted from the placenta and the umbilical cord. Such a procedure would be fast, being completed before coagulation and collapse of vessels reduces the amount of blood collected, and employ a semi-automatic collection device that would not require any special skill on part of the collector to use. In addition, contamination must be prevented, and the collection kit should be disposable and inexpensive.
It is an object of this invention to provide an apparatus, which comprises a hermetically closed and disinfected device for collecting cord blood.
It is another object of this invention to provide a method of using said apparatus for collecting cord blood, which will overcome the drawbacks of the prior art mainly by increasing the amount of uncontaminated blood collected so that the number of stem cells extracted will be sufficient for transplanting in a grown person.
It is another object of this invention to provide an improved apparatus and method for a closed-circuit collection of cord blood.
It is another object of this invention to provide an apparatus which even an inexperienced person can use efficiently.
It is a further object of this invention to provide a comparatively fast method of collecting cord blood.
It is another purpose of this invention is to provide an inexpensive, disposable collection kit.
Other purposes and advantages of this invention will appear as the description proceeds.